Seeking sources: Mathematics of knots

Hello everyone,

First of all, I posted this thread here because I really wasn't too sure where else to. I suppose it could have gone in the "Analysis, Topology and Differential Geometry" section, but this isn't exactly university level... well, I'll explain. I apologise if the thread would have been better suited to another section.

I am planning to write my extended essay (a (maximum) 4000 word piece of research carried out approximately March through December) on knots in mathematics. I was wondering whether anyone might have suggestions of books, websites or any other kind of source for information on this subject (in principle simply to get a rough idea of the topic(s) involved)? My maths level is... well, I am studying High Level Mathematics in the International Baccalaureate (IB), 11th grade (for those of you to whom this means nothing, I hear that IB High Level Maths is comparable to or slightly harder than A-leve

Further Mathematics, but don't quote me on this. I'm afraid I don't know about the american system). I am aware that this topic may prove to be too ambitious, but I'm going to give it a go; I am willing to learn. Thank you in advance for any help.

Dan